Exactly.I will agree that there are one or two events where Maria's behavior could use some slight adjustments (particularly the Ellen related ones) However, the complaint overall, that doesn't quite make sense to me. Why wouldn't the clearly bisexual and openly flirty character who enjoys seeing her man enjoy himself, even with other women, not behave the way she does? It's not uncommon, especially in polyamorous relationships, for any member to wingman for other people in the relationship, and it's very common in more swinger focused relationships for one partner to do a lot of this.
So... either your issue is that you don't like a sexually assertive character, or you just don't understand Maria.
People are going to be a lot less threatened by the offer of something like that, if the partner who is "being cheated on" (by most standards) is the one doing the asking (particularly if the one asking is a woman).
MC: Hey, Baby. Want to have a threesome with me and my girl?
Maria: Hey, Babe. Want to have fun with my man? Let's go play!
Which do you think has a better shot?